In this document, IP refers to IP Version 4 (IPv4) unless there is a specific reference to IP Version 6 (IPv6).

Note The examples in this document are for a Catalyst 3750-E switch. When showing an interface in a command-line interface (CLI) command, the example is on the Catalyst 3750-E switch, for example, gigabitethernet 1/0/5. The examples also apply to the Catalyst 3560-E switch. In the previous example, the specified interface on a Catalyst 3560-E switch is gigabitethernet0/5 (without the stack member number of 1/).

•IP services feature set, which provides a richer set of enterprise-class intelligent services and full IPv6 support. It includes all IP base features plus full Layer 3 routing (IP unicast routing, IP multicast routing, and fallback bridging). The IP services feature set includes protocols such as the Enhanced Interior Gateway Routing Protocol (EIGRP) and the Open Shortest Path First (OSPF) Protocol. This feature set also supports all IP service features with IPv6 routing and IPv6 ACLs and Multicast Listener Discovery (MLD) snooping.

Note Unless otherwise noted, all features described in this chapter and in this guide are supported on all feature sets.

Deployment Features

•Express Setup for quickly configuring a switch for the first time with basic IP information, contact information, switch and Telnet passwords, and Simple Network Management Protocol (SNMP) information through a browser-based program. For more information about Express Setup, see the getting started guide.

•User-defined and Cisco-default Smartports macros for creating custom switch configurations for simplified deployment across the network.

•Auto Smartports Cisco-default and user-defined macros for dynamic port configuration based on the device type detected on the port.

•AutoSmartPort enhancements in Cisco IOS Release 12.2(55)SE, which adds support for macro persistency, LLDP-based triggers, MAC address and OUI-based triggers, remote macros as well as for automatic configuration based on these two new device types: Cisco Digital Media Player (Cisco DMP) and Cisco IP Video Surveillance Camera (Cisco IPVSC).

•Auto Smartport features in Cisco IOS Release 15.0(1)SE with improved device classification capabilities and accuracy, increased device visibility, and enhanced macro management. The device classifier is enabled by default, and can classify devices based on DHCP options.

•An embedded device manager GUI for configuring and monitoring a single switch through a web browser. For information about starting the device manager, see the getting started guide. For more information about the device manager, see the switch online help.

•Cisco Network Assistant (referred to as Network Assistant) for

–Managing communities, which are device groups like clusters, except that they can contain routers and access points and can be made more secure.

–Interactive guide mode that guides you in configuring complex features such as VLANs, ACLs, and quality of service (QoS).

–Configuration wizards that prompt you to provide only the minimum required information to configure complex features such as QoS priorities for video traffic, priority levels for data applications, and security.

–Downloading an image to a switch.

–Applying actions to multiple ports and multiple switches at the same time, such as VLAN and QoS settings, inventory and statistic reports, link- and switch-level monitoring and troubleshooting, and multiple switch software upgrades.

–Viewing a topology of interconnected devices to identify existing switch clusters and eligible switches that can join a cluster and to identify link information between switches.

–Monitoring real-time status of a switch or multiple switches from the LEDs on the front-panel images. The system, redundant power system (RPS), system and port LED colors on the images are similar to those used on the physical LEDs.

•Cisco StackWise Plus technology on Catalyst 3750-E switches for

–Connecting up to nine switches through their StackWise Plus ports that operate as a single switch or switch-router in the network.

–Creating a bidirectional 32-Gb/s switching fabric across the switch stack, with all stack members having full access to the system bandwidth.

–Using a single IP address and configuration file to manage the entire switch stack.

–Automatic Cisco IOS version-check of new stack members with the option to automatically load images from the stack master or from a TFTP server.

–Adding, removing, and replacing switches in the stack without disrupting the operation of the stack.

–Provisioning a new member for a switch stack with the offline configuration feature. You can configure in advance the interface configuration for a specific stack member number and for a specific switch type of a new switch that is not part of the stack. The switch stack retains this information across stack reloads whether or not the provisioned switch is part of the stack.

–Displaying stack-ring activity statistics (the number of frames sent by each stack member to the ring).

–Rolling stack upgrade to minimize network disruption when the members of a switch stack are upgraded one at a time.

For information about the stacking interactions in Catalyst 3750-X, Catalyst 3750-E, and 3750 mixed switch stacks, see Chapter 5 "Managing Switch Stacks" and the Cisco Software Activation and Compatibility Document on Cisco.com.

–Automatic discovery of candidate switches and creation of clusters of up to 16 switches that can be managed through a single IP address.

–Extended discovery of cluster candidates that are not directly connected to the command switch.

•Smart Install to allow a single point of management (director) in a network. You can use Smart Install to provide zero touch image and configuration upgrade of newly deployed switches and image and configuration downloads for any client switches. For more information, see the Cisco Smart Install Configuration Guide on Cisco.com.

•Smart Install enhancements in Cisco IOS Release 12.2(58)SE including the ability to manually change a client switch health state from denied to allowed or hold for on-demand upgrades, to remove selected clients from the director database, to allow simultaneous on-demand upgrade of multiple clients, and to provide more information about client devices, including device status, health status, and upgrade status.

•Call Home to provide e-mail-based and web-based notification of critical system events. Users with a service contract directly with Cisco Systems can register Call Home devices for the Cisco Smart Call Home service that generates automatic service requests with the Cisco TAC.

Management Options

•An embedded device manager—The device manager is a GUI that is integrated in the universal software image. You use it to configure and to monitor a single switch. For information about starting the device manager, see the getting started guide. For more information about the device manager, see the switch online help.

•Network Assistant—Network Assistant is a network management application that can be downloaded from Cisco.com. You use it to manage a single switch, a cluster of switches, or a community of devices. For more information about Network Assistant, see Getting Started with Cisco Network Assistant, available on Cisco.com.

•CLI—The Cisco IOS software supports desktop- and multilayer-switching features. You can access the CLI by connecting your management station directly to the switch console port, by connecting your PC directly to the Ethernet management port, or by using Telnet from a remote management station or PC. You can manage the switch stack by connecting to the console port or Ethernet management port of any stack member. For more information about the CLI, see Chapter 2 "Using the Command-Line Interface."

•SNMP—SNMP management applications such as CiscoWorks2000 LAN Management Suite (LMS) and HP OpenView. You can manage from an SNMP-compatible management station or a PC that is running platforms such as HP OpenView or SunNet Manager. The switch supports a comprehensive set of MIB extensions and four remote monitoring (RMON) groups. For more information about using SNMP, see Chapter 33 "Configuring SNMP."

•Cisco IOS Configuration Engine (previously known to as the Cisco IOS CNS agent)-—Configuration service automates the deployment and management of network devices and services. You can automate initial configurations and configuration updates by generating switch-specific configuration changes, sending them to the switch, executing the configuration change, and logging the results.

•DHCP-based autoconfiguration and image update to download a specified configuration a new image to a large number of switches

•Source Specific Multicast (SSM) mapping for multicast applications to provide a mapping of source to allowing IGMPv2 clients to utilize SSM, allowing listeners to connect to multicast sources dynamically and reducing dependencies on the application

•The HTTP client in Cisco IOS supports can send requests to both IPv4 and IPv6 HTTP servers, and the HTTP server in Cisco IOS can service HTTP requests from both IPv4 and IPv6 HTTP clients

•Simple Network and Management Protocol (SNMP) can be configured over IPv6 transport so that an IPv6 host can send SNMP queries and receive SNMP notifications from a device running IPv6.

•IPv6 supports stateless autoconfiguration to manage link, subnet, and site addressing changes, such as management of host and mobile IP addresses

•IETF IP-MIB and IP-FORWARD-MIB(RFC4292 and RFC4293) updates to support the IP version 6 (IPv6)-only and the IPv6 part of the protocol-version independent (PVI) objects and tables.

•Local web authentication banner so that custom banner or image file can be displayed at a web authentication login screen

•CPU utilization threshold trap monitors CPU utilization

•LLDP-MED network-policy profile time, length, value (TLV) for creating a profile for voice and voice-signalling by specifying the values for VLAN, class of service (CoS), differentiated services code point (DSCP), and tagging mode

•Support for including a hostname in the option 12 field of DHCPDISCOVER packets. This provides identical configuration files to be sent by using the DHCP protocol

•DHCP Snooping enhancement to support the selection of a fixed string-based format for the circuit-id sub-option of the Option 82 DHCP field

•Increased support for LLPD-MED by allowing the switch to grant power to the power device (PD), based on the power policy TLV request

•IEEE 802.1s Multiple Spanning Tree Protocol (MSTP) for grouping VLANs into a spanning-tree instance and for providing multiple forwarding paths for data traffic and load-balancing and rapid per-VLAN Spanning-Tree plus (rapid-PVST+) based on the IEEE 802.1w Rapid Spanning Tree Protocol (RSTP) for rapid convergence of the spanning tree by immediately changing root and designated ports to the forwarding state

•Optional spanning-tree features available in PVST+, rapid-PVST+, and MSTP mode:

–Port Fast for eliminating the forwarding delay by enabling a port to immediately change from the blocking state to the forwarding state

–Loop guard for preventing alternate or root ports from becoming designated ports because of a failure that leads to a unidirectional link

•Equal-cost routing for link-level and switch-level redundancy

•Flex Link Layer 2 interfaces to back up one another as an alternative to STP for basic link redundancy

•Link-state tracking to mirror the state of the ports that carry upstream traffic from connected hosts and servers and to allow the failover of the server traffic to an operational link on another Cisco Ethernet switch

•RPS support through the Cisco Redundant Power System 2300, also referred to as the RPS 2300, for enhancing power reliability, configuring and managing the redundant power system. For more information about the RPS 2300, see the Cisco Redundant Power System 2300 Hardware Installation Guide that shipped with the device and that is also on Cisco.com

VLAN Features

•Support for up to 1005 VLANs for assigning users to VLANs associated with appropriate network resources, traffic patterns, and bandwidth

•Support for VLAN IDs in the 1 to 4094 range as allowed by the IEEE 802.1Q standard

•VLAN Query Protocol (VQP) for dynamic VLAN membership

•Inter-Switch Link (ISL) and IEEE 802.1Q trunking encapsulation on all ports for network moves, adds, and changes; management and control of broadcast and multicast traffic; and network security by establishing VLAN groups for high-security users and network resources

•Dynamic Trunking Protocol (DTP) for negotiating trunking on a link between two devices and for negotiating the type of trunking encapsulation (IEEE 802.1Q or ISL) to be used

•VLAN 1 minimization for reducing the risk of spanning-tree loops or storms by allowing VLAN 1 to be disabled on any individual VLAN trunk link. With this feature enabled, no user traffic is sent or received on the trunk. The switch CPU continues to send and receive control protocol frames.

•Private VLANs to address VLAN scalability problems, to provide a more controlled IP address allocation, and to allow Layer 2 ports to be isolated from other ports on the switch

•Port security on a PVLAN host to limit the number of MAC addresses learned on a port, or define which MAC addresses may be learned on a port

•Support for VTP version 3 that includes support for configuring extended range VLANs (VLANs 1006 to 4094) in any VTP mode, enhanced authentication (hidden or secret passwords), propagation of other databases in addition to VTP, VTP primary and secondary servers, and the option to turn VTP on or off by port

Security Features

•Web authentication to allow a supplicant (client) that does not support IEEE 802.1x functionality to be authenticated using a web browser.

•IP source guard to restrict traffic on nonrouted interfaces by filtering traffic based on the DHCP snooping database and IP source bindings

•Dynamic ARP inspection to prevent malicious attacks on the switch by not relaying invalid ARP requests and responses to other ports in the same VLAN

•IEEE 802.1Q tunneling so that customers with users at remote sites across a service-provider network can keep VLANs segregated from other customers and Layer 2 protocol tunneling to ensure that the customer's network has complete STP, CDP, and VTP information about all users

–Support for VLAN assignment on a port configured for multi-auth mode. The RADIUS server assigns a VLAN to the first host to authenticate on the port, and subsequent hosts use the same VLAN. Voice VLAN assignment is supported for one IP phone

–Port security for controlling access to IEEE 802.1x ports

–Voice VLAN to permit a Cisco IP Phone to access the voice VLAN regardless of the authorized or unauthorized state of the port

–Restricted VLAN to provide limited services to users who are IEEE 802.1x compliant, but do not have the credentials to authenticate via the standard IEEE 802.1x processes

–IEEE 802.1x accounting to track network usage

–IEEE 802.1x with wake-on-LAN to allow dormant PCs to be powered on based on the receipt of a specific Ethernet frame

–Voice aware IEEE 802.1x security to apply traffic violation actions only on the VLAN on which a security violation occurs

–Network Edge Access Topology (NEAT) with 802.1x switch supplicant, host authorization with CISP, and auto enablement to authenticate a switch outside a wiring closet as a supplicant to another switch.

–NEAT enhancement to control access to the supplicant port during authentication

–Multiple-user authentication to allow more than one host to authenticate on an 802.1x-enabled port.

–MAC authentication bypass to authorize clients based on the client MAC address.

–Critical voice VLAN to so that when authentication is enabled and the access control server is not available, traffic from the host tagged with the voice VLAN is put into the configured voice VLAN for the port

–Voice aware IEEE 802.1x and mac authentication bypass (MAB) security violation to shut down only the data VLAN on a port when a security violation occurs

•Network Admission Control (NAC) features:

–NAC Layer 2 IEEE 802.1x validation of the antivirus condition or posture of endpoint systems or clients before granting the devices network access.

•IEEE 802.1x readiness check to determine the readiness of connected end hosts before configuring IEEE 802.1x on the switch

•Support for IP source guard on static hosts

•RADIUS Change of Authorization (CoA) to change the attributes of a certain session after it is authenticated. When there is a change in policy for a user or user group in AAA, administrators can send the RADIUS CoA packets from the AAA server, such as Cisco Secure ACS to reinitialize authentication, and apply to the new policies

•IEEE 802.1x User Distribution to allow deployments with multiple VLANs (for a group of users) to improve scalability of the network by load balancing users across different VLANs. Authorized users are assigned to the least populated VLAN in the group, assigned by RADIUS server

•Support for critical VLAN with multiple-host authentication so that when a port is configured for multi-auth, and an AAA server becomes unreachable, the port is placed in a critical VLAN in order to still permit access to critical resources

•Support for Network Edge Access Topology (NEAT) to change the port host mode and to apply a standard port configuration on the authenticator switch port

•VLAN-ID based MAC authentication to use the combined VLAN and MAC address information for user authentication to prevent network access from unauthorized VLANs

•MAC move to allow hosts (including the hosts connected behind an IP phone) to move across ports within the same switch without any restrictions to enable mobility. With MAC move, the switch treats the reappearance of the same MAC address on another port in the same way as a completely new MAC address

•Support for 3DES and AES with version 3 of the Simple Network Management Protocol (SNMPv3). This release adds support for the 168-bit Triple Data Encryption Standard (3DES) and the 128-bit, 192-bit, and 256-bit Advanced Encryption Standard (AES) encryption algorithms to SNMPv3

•Support for the Security Group Tag (SCT) Exchange Protocol (SXP) component of Cisco TrustSec, a security architecture using authentication, encryption, and access control

–IP ToS/DSCP and IEEE 802.1p CoS marking based on flow-based packet classification (classification based on information in the MAC, IP, and TCP/UDP headers) for high-performance quality of service at the network edge, allowing for differentiated service levels for different types of network traffic and for prioritizing mission-critical traffic in the network

–Trusted port states (CoS, DSCP, and IP precedence-both IPv4 and IPv6) within a QoS domain and with a port bordering another QoS domain

–Trusted boundary for detecting the presence of a Cisco IP Phone, trusting the CoS value received, and ensuring port security

•Policing

–Traffic-policing policies on the switch port for managing how much of the port bandwidth should be allocated to a specific traffic flow

–If you configure multiple class maps for a hierarchical policy map, each class map can be associated with its own port-level (second-level) policy map. Each second-level policy map can have a different policer.

–Weighted tail drop (WTD) as the congestion-avoidance mechanism for managing the queue lengths and providing drop precedences for different traffic classifications

–Shaped round robin (SRR) as the scheduling service for specifying the rate at which packets are sent to the stack or internal ring (sharing is the only supported mode on ingress queues)

•Egress queues and scheduling

–Four egress queues per port

–WTD as the congestion-avoidance mechanism for managing the queue lengths and providing drop precedences for different traffic classifications

–SRR as the scheduling service for specifying the rate at which packets are dequeued to the egress interface (shaping or sharing is supported on egress queues). Shaped egress queues are guaranteed but limited to using a share of port bandwidth. Shared egress queues are also guaranteed a configured share of bandwidth, but can use more than the guarantee if other queues become empty and do not use their share of the bandwidth.

•Automatic quality of service (QoS) voice over IP (VoIP) enhancement for port -based trust of DSCP and priority queuing for egress traffic

•IPv6 port-based trust with dual IPv4 and IPv6 SDM templates

•Full QoS support for IPv6 traffic

Layer 3 Features

Note Some features noted are available only in the IP services feature set.

•Support for these IP services, making them VRF aware so that they can operate on multiple routing instances: HSRP, uRPF, ARP, SNMP, IP SLA, TFTP, FTP, syslog, traceroute, and ping

•Fallback bridging for forwarding non-IP traffic between two or more VLANs (requires the IP services feature set)

•Static IP routing for manually building a routing table of network path information.

•Equal-cost routing for load-balancing and redundancy

•Internet Control Message Protocol (ICMP) and ICMP Router Discovery Protocol (IRDP) for using router advertisement and router solicitation messages to discover the addresses of routers on directly attached subnets.

•Protocol-Independent Multicast (PIM) for multicast routing within the network, allowing for devices in the network to receive the multicast feed requested and for switches not participating in the multicast to be pruned. Includes support for PIM sparse mode (PIM-SM), PIM dense mode (PIM-DM), and PIM sparse-dense mode (requires the IP services feature set).

•Support for the SSM PIM protocol to optimize multicast applications, such as video.

•Nonstop forwarding (NSF) awareness to enable the Layer 3 switch to continue forwarding packets from an NSF-capable neighboring router when the primary route processor (RP) is failing and the backup RP is taking over, or when the primary RP is manually reloaded for a nondisruptive software upgrade (requires the IP services feature set).

•NSF-capable routing for OSPF and EIGRP that allows the switch to rebuild routing tables based on information from NSF-aware and NSF-capable neighbors (only Catalyst 3750-E switches).

•Support for the Virtual Router Redundancy Protocol (VRRP) for IPv4, which dynamically assigns responsibility for one or more virtual routers to the VRRP routers on a LAN, allowing multiple routers on a multiaccess link to utilize the same virtual IP address.

Power over Ethernet Features

•Ability to provide power to connected Cisco pre-standard and IEEE 802.3af-compliant powered devices from Power over Ethernet (PoE)-capable ports if the switch detects that there is no power on the circuit.

Cisco IOS Release 12.2(44)SE and later supports enhanced PoE. An enhanced PoE port can support any additional powered device that requires up to 20 W of power, such as a Cisco AP1250 wireless access point.

•Support for CDP with power consumption. The powered device notifies the switch of the amount of power it is consuming.

•Support for Cisco intelligent power management. The powered device and the switch negotiate through power-negotiation CDP messages for an agreed power-consumption level. The negotiation allows a high-power Cisco powered device to operate at its highest power mode.

•Automatic detection and power budgeting; the switch maintains a power budget, monitors and tracks requests for power, and grants power only when it is available.

•Ability to monitor the real-time power consumption. On a per-PoE port basis, the switch senses the total power consumption, polices the power usage, and reports the power usage.

•IP Service Level Agreements (IP SLAs) support to measure network performance by using active traffic monitoring.

•IP SLAs EOT to use the output from IP SLAs tracking operations triggered by an action such as latency, jitter, or packet loss for a standby router failover takeover.

•EOT and IP SLAs EOT static route support to identify when a preconfigured static route or a DHCP route goes down.

•Support for the Built-in Traffic Simulator using Cisco IOS IP SLAs video operations to generate synthetic traffic for a variety of video applications, such as Telepresence, IPTV and IP video surveillance camera. You can use the simulator tool:

•Cisco Medianet to enable intelligent services in the network infrastructure for a wide variety of video applications. One of the services of Medianet is auto provisioning for Cisco Digital Media Players and Cisco IP Video Surveillance cameras through Auto Smartports.

•Cisco Mediatrace and performance monitor

–Cisco Mediatrace to troubleshoot and isolate network or application issues in traffic streams. It helps drill down to analyze one-way delay, one-way packet loss, one-way jitter, and connectivity in IPv4 networks that carry video traffic. This tool can be used for any UDP-based video or non-video traffic stream .

For information:http://www.cisco.com/en/US/docs/ios/media_monitoring/configuration/guide/15_1m_and_t/mm_15_1m_and_t.html

–Cisco Application Performance Monitor to track the video packet flow and to troubleshoot and isolate performance degradation in traffic streams. You can use the performance monitor for both video and nonvideo traffic .

For information:http://www.cisco.com/en/US/docs/ios/media_monitoring/command/reference/mm_book.html

–Configuration guidelines for Mediatrace and performance monitor:

Video monitoring is supported only on physical ports. It is not supported on EtherChannels.

When a switch receives excessive traffic, packets are dropped.

The switch supports policy maps and port-based trust only on ingress ports.

–Limitations for Mediatrace and performance monitor:

You cannot configure video monitoring and a router or VLAN ACL on the same interface.If you configure video monitoring before configuring the ACL, the ACL settings override the video monitoring settings, and a message appears.If you configure the ACL before configuring video monitoring, the switch rejects the video monitoring commands, and a message appears.

As video monitoring packets pass through the network queues, they can be dropped.

The switch cannot match lost or dropped packets to a specific traffic or data flow. For information about these packets, see the ingress and egress QoS counters.

Default Settings After Initial Switch Configuration

The switch is designed for plug-and-play operation, requiring only that you assign basic IP information to the switch and connect it to the other devices in your network. If you have specific network needs, you can change the interface-specific and system- and stack-wide settings.

Note For information about assigning an IP address by using the browser-based Express Setup program, see the getting started guide. For information about assigning an IP address by using the CLI-based setup program, see the hardware installation guide.

If you do not configure the switch at all, the switch operates with these default settings:

Network Configuration Examples

This section provides network configuration concepts and includes examples of using the switch to create dedicated network segments and interconnecting the segments through Gigabit Ethernet and 10-Gigabit Ethernet connections.

Design Concepts for Using the Switch

As your network users compete for network bandwidth, it takes longer to send and receive data. When you configure your network, consider the bandwidth required by your network users and the relative priority of the network applications that they use.

Table 1-1 describes what can cause network performance to degrade and how you can configure your network to increase the bandwidth available to your network users.

Table 1-1 Increasing Network Performance

Network Demands

Suggested Design Methods

Too many users on a single network segment and a growing number of users accessing the Internet

•Create smaller network segments so that fewer users share the bandwidth, and use VLANs and IP subnets to place the network resources in the same logical network as the users who access those resources most.

•Use full-duplex operation between the switch and its connected workstations.

•Increased power of new PCs, workstations, and servers

•High bandwidth demand from networked applications (such as e-mail with large attached files) and from bandwidth-intensive applications (such as multimedia)

•Connect global resources—such as servers and routers to which the network users require equal access—directly to the high-speed switch ports so that they have their own high-speed segment.

•Use the EtherChannel feature between the switch and its connected servers and routers.

Bandwidth alone is not the only consideration when designing your network. As your network traffic profiles evolve, consider providing network services that can support applications for voice and data integration, multimedia integration, application prioritization, and security. Table 1-2 describes some network demands and how you can meet them.

•Use other QoS mechanisms such as packet classification, marking, scheduling, and congestion avoidance to classify traffic with the appropriate priority level, thereby providing maximum flexibility and support for mission-critical, unicast, and multicast, and multimedia applications.

•Use MVR to continuously send multicast streams in a multicast VLAN but to isolate the streams from subscriber VLANs for bandwidth and security reasons.

High demand on network redundancy and availability to provide always on mission-critical applications

•Use switch stacks, where all stack members are eligible stack masters in case of stack-master failure. All stack members have synchronized copies of the saved and running configuration files of the switch stack.

A growing demand for using existing infrastructure to transport data and voice from a home or office to the Internet or an intranet at higher speeds

Use the Catalyst Long-Reach Ethernet (LRE) switches to provide up to 15 Mb of IP connectivity over existing infrastructure, such as existing telephone lines.

Note LRE is the technology used in the Catalyst 2950 LRE switch. See the documentation sets specific to this switch for LRE information.

You can use the switches and switch stacks to create the following:

•Cost-effective wiring closet (Figure 1-1)—A cost-effective way to connect many users to the wiring closet is to have a switch stack of up to nine Catalyst 3750-E switches. To preserve switch connectivity if one switch in the stack fails, connect the switches as recommended in the hardware installation guide, and enable either cross-stack Etherchannel or cross-stack UplinkFast.

You can have redundant uplink connections, using SFP modules in the switch stack to a Gigabit backbone switch, such as a Catalyst 4500, Catalyst 3750-X, Catalyst 3750-E, or Catalyst 3560E-12D switch. You can also create backup paths by using Gigabit or EtherChannel links. If one of the redundant connections fails, the other can serve as a backup path. If the Gigabit switch is cluster-capable, you can configure it and the switch stack as a switch cluster to manage them through a single IP address. The Gigabit switch can be connected to a Gigabit server through a 1000BASE-T connection.

Figure 1-1 Cost-Effective Wiring Closet

•High-performance wiring closet (Figure 1-2)—For high-speed access to network resources, you can use Catalyst 3750-E switches and switch stacks in the access layer to provide Gigabit Ethernet access to the desktop. To prevent congestion, use QoS DSCP marking priorities on these switches. For high-speed IP forwarding at the distribution layer, connect the switches in the access layer to a Gigabit multilayer switch in the backbone, such as a Catalyst 4500 Gigabit switch or Catalyst 6500 Gigabit switch.

•Cost-effective Gigabit-to-the-desktop (GTD) access for high-performance workgroups (Figure 1-3)—For high-speed access to network resources, you can use the Catalyst 3560-E switches in the access layer to provide Gigabit Ethernet to the desktop. To prevent congestion, use QoS DSCP marking priorities on these switches. For high-speed IP forwarding at the distribution layer, connect the switches in the access layer to a Gigabit switch with routing capability or to a router.

The first illustration is of an isolated high-performance workgroup, where the Catalyst 3560-E switches are connected to Catalyst 3750-E switches in the distribution layer. The second illustration is of a high-performance workgroup in the branch office, where the Catalyst 3560-E switches are connected to a router in the distribution layer.

Each switch in this configuration provides users with a dedicated 1-Gb/s connection to network resources. Using SFP modules also provides flexibility in media and distance options through fiber-optic connections.

•Redundant Gigabit backbone (Figure 1-4)—Using HSRP, you can create backup paths between two Catalyst 3750-E Gigabit switches to enhance network reliability and load-balancing for different VLANs and subnets. Using HSRP also provides faster network convergence if any network failure occurs. You can connect the Catalyst switches, again in a star configuration, to two Catalyst 3750-E backbone switches. If one of the backbone switches fails, the second backbone switch preserves connectivity between the switches and network resources.

Figure 1-4 Redundant Gigabit Backbone

•Server aggregation (Figure 1-5) and Linux server cluster (Figure 1-6)—You can use the Catalyst 3560-E switches and Catalyst 3750-E-only switch stacks to interconnect groups of servers, centralizing physical security and administration of your network. For high-speed IP forwarding at the distribution layer, connect the switches in the access layer to multilayer switches with routing capability. The Gigabit interconnections minimize latency in the data flow.

QoS and policing on the switches provide preferential treatment for certain data streams. They segment traffic streams into different paths for processing. Security features on the switch ensure rapid handling of packets.

Fault tolerance from the server racks to the core is achieved through dual homing of servers connected to dual switch stacks or the switches, which have redundant Gigabit EtherChannels and cross-stack EtherChannels.

Using dual SFP module uplinks from the switches provides redundant uplinks to the network core. Using SFP modules provides flexibility in media and distance options through fiber-optic connections.

The various lengths of stack cable available, ranging from 0.5 meter to 3 meters, provide extended connections to the switch stacks across multiple server racks, for multiple stack aggregation.

Figure 1-5 Server Aggregation

Figure 1-6 Linux Server Cluster

Small to Medium-Sized Network Using Catalyst 3750-E and 3560-E Switches

Figure 1-7 and Figure 1-8 show a configuration for a network of up to 500 employees. This network uses aCatalyst 3750-E-only Layer 3 switch stack or Catalyst 3560-E Layer 3 switches with high-speed connections to two routers. For network reliability and load-balancing, this network has HSRP enabled on the routers and on the switches. This ensures connectivity to the Internet, WAN, and mission-critical network resources in case one of the routers or switches fails. The switches are using routed uplinks for faster failover. They are also configured with equal-cost routing for load sharing and redundancy. (When the network uses Catalyst 3750-E switches, a Layer 2 switch stack can use cross-stack EtherChannel for load sharing.)

The switches are connected to workstations, and local servers, and IEEE 802.3af compliant and noncompliant powered devices (such as Cisco IP Phones). The server farm includes a call-processing server running Cisco CallManager software. Cisco CallManager controls call processing, routing, and Cisco IP Phone features and configuration. The switches are interconnected through Gigabit interfaces.

This network uses VLANs to logically segment the network into well-defined broadcast groups and for security management. Data and multimedia traffic are configured on the same VLAN. Voice traffic from the Cisco IP Phones are configured on separate VVIDs. If data, multimedia, and voice traffic are assigned to the same VLAN, only one VLAN can be configured per wiring closet.

When an end station in one VLAN needs to communicate with an end station in another VLAN, a router or Layer 3 switch routes the traffic to the destination VLAN. In this network, the Catalyst 3750-E-onlyswitch stack or Catalyst 3560-E switches are providing inter-VLAN routing. VLAN access control lists (VLAN maps) on the switch stack or switch provide intra-VLAN security and prevent unauthorized users from accessing critical areas of the network.

In addition to inter-VLAN routing, the multilayer switches provide QoS mechanisms such as DSCP priorities to prioritize the different types of network traffic and to deliver high-priority traffic. If congestion occurs, QoS drops low-priority traffic to allow delivery of high-priority traffic.

Catalyst PoE switch ports automatically detect any Cisco pre-standard and IEEE 802.3af-compliant powered devices that are connected. Each PoE switch port provides 15.4 W of power per port. The powered device, such as a Cisco IP Phone, can receive redundant power when it is also connected to an AC power source. Powered devices not connected to Catalyst PoE switches must be connected to AC power sources to receive power.

Large Network Using Catalyst 3750-E and 3560-E Switches

Switches in the wiring closet have traditionally been only Layer 2 devices, but as network traffic profiles evolve, switches in the wiring closet are increasingly employing multilayer services such as multicast management and traffic classification. Figure 1-9 shows a configuration for a network that uses only Catalyst 3750-E switch stacks in the wiring closets and two backbone switches, such as the Catalyst 6500 switches, to aggregate up to ten wiring closets. Figure 1-10 shows a configuration for a network that uses only Catalyst 3560-E switches in the wiring closets and two backbone switches, such as the Catalyst 6500 switches, to aggregate up to ten wiring closets.

In the wiring closet, each switch stack or switch has IGMP snooping enabled to efficiently forward multimedia and multicast traffic. QoS ACLs that either drop or mark nonconforming traffic based on bandwidth limits are also configured on each switch stack or switch. VLAN maps provide intra-VLAN security and prevent unauthorized users from accessing critical pieces of the network. QoS features can limit bandwidth on a per-port or per-user basis. The switch ports are configured as either trusted or untrusted. You can configure a trusted port to trust the CoS value, the DSCP value, or the IP precedence. If you configure the port as untrusted, you can use an ACL to mark the frame in accordance with the network policy.

Each switch stack or switch provides inter-VLAN routing. They provide proxy ARP services to get IP and MAC address mapping, thereby removing this task from the routers and decreasing this type of traffic on the WAN links. These switch stacks or switches also have redundant uplink connections to the backbone switches, with each uplink port configured as a trusted routed uplink to provide faster convergence in case of an uplink failure.

The routers and backbone switches have HSRP enabled for load-balancing and redundant connectivity to guarantee mission-critical traffic.

Multidwelling Network Using Catalyst 3750-E Switches

A growing segment of residential and commercial customers are requiring high-speed access to Ethernet metropolitan-area networks (MANs). Figure 1-11 shows a configuration for a Gigabit Ethernet MAN ring using multilayer switch stacks as aggregation switches in the mini-point-of-presence (POP) location. These switches are connected through 1000BASE-X SFP module ports.

The resident switches can be Catalyst 3750-E switches, providing customers with high-speed connections to the MAN. The Catalyst 2950 LRE switch can also be used as a residential switch for customers requiring connectivity through existing phone lines. The Catalyst 2950 LRE switch can then connect to another residential switch or to a Catalyst 3750 aggregation switch. For more information about the Catalyst Long-Reach Ethernet (LRE) switches, see the documentation sets specific to these switches for LRE information.

All ports on the residential Catalyst 3750-E switches (and Catalyst 2950 LRE switches if they are included) are configured as IEEE 802.1Q trunks with protected port and STP root guard features enabled. The protected port feature provides security and isolation between ports on the switch, ensuring that subscribers cannot view packets destined for other subscribers. STP root guard prevents unauthorized devices from becoming the STP root switch. All ports have IGMP snooping or CGMP enabled for multicast traffic management. ACLs on the uplink ports to the aggregating Catalyst 3750 multilayer switches provide security and bandwidth management.

Long-Distance, High-Bandwidth Transport Configuration

Figure 1-12 shows a configuration for sending 8 Gigabits of data over a single fiber-optic cable. The Catalyst 3750-E or 3560-E switches have coarse wavelength-division multiplexing (CWDM) fiber-optic SFP modules installed. Depending on the CWDM SFP module, data is sent at wavelengths from 1470 to 1610 nm. The higher the wavelength, the farther the transmission can travel. A common wavelength used for long-distance transmissions is 1550 nm.

The CWDM SFP modules connect to CWDM optical add/drop multiplexer (OADM) modules over distances of up to 393,701 feet (74.5 miles or 120 km). The CWDM OADM modules combine (or multiplex) the different CWDM wavelengths, allowing them to travel simultaneously on the same fiber-optic cable. The CWDM OADM modules on the receiving end separate (or demultiplex) the different wavelengths.

For more information about the CWDM SFP modules and CWDM OADM modules, see the Cisco CWDM GBIC and CWDM SFP Installation Note.

Figure 1-12 Long-Distance, High-Bandwidth Transport Configuration

Where to Go Next

Before configuring the switch, review these sections for startup information: